Slashdot is powered by your submissions, so send in your scoop

 


Forgot your password?
Close
typodupeerror
×
Technology

3Com's "Gamer" Modem Pings Faster? 154

Posted by CmdrTaco from the wait-a-minute dept.
An anonymous reader pointed us to 3Coms Gamer Modem: they claim faster ping times and better online play. I'm more than a little skeptical here, does anyone have more info?
This discussion has been archived. No new comments can be posted.

3Com's "Gamer" Modem Pings Faster? More

3Com's "Gamer" Modem Pings Faster?

Comments Filter:
  • >Hang on -- how can you get a faster ping if the
    >pinged server is down, if there is some Internet
    >congestion or if there is a backhoe (snip!)
    >between you and the machine? =)

    Ok, I'm gonna hope the smiley means this one's a joke, but...

    In a modem connection, the modem is often (usually) the slowest link (100+ ms). If they can shave even 25% of that off, it will make a noticable difference in internet gaming.

    Of course they can't do anything about the connections on the other side - but every little bit at any step of the way certainly helps.

    -LjM


  • It is perfectly possible to get faster ping times than usually achieved with V.90 ( 56K ) modems.

    A lot of the time involved in the entire round trip of a ping, from application to remote system to application is handled in software or firmware on the modem itself. If 3Com has drastically improved the handling of the response at the hardware level to eliminate a bottleneck, then yes, you can get faster pings. Of course, this assumes that the server at the remote end is up. V.90 maxes out at 53K, by the way, and achieves that in one direction only. Just why is beyond the current scope, but there is an excellent V.90 intro on the 3Com site. No, I do not work for 3Com, but I deal with V.90 and the like every day ;)

  • Does that come with the Internet Mousepad, you know, the mouse pad 'specilaly made for surfing the Internet?

  • Ummm... Logitech ACTUALLY makes gamer mice... I thought it was pretty funny when I saw them on the Logitech web page a while back.

    Logitech Gaming Mouse @ http://www.logitech.com/us/products/gm10_100.html [logitech.com]

    BTW, look at the "features" it has... no different from any other 3-button mouse.

  • Why was this marked insightful? It is a freaking question! (An a wrong assumtion.) No offense to the poster, just the moderator. Anyway, to answer your question, most modems ARE hardware based. No real gamer uses a software modem for quake (I have a software modem, don't laugh, just waiting for the DSL installer to get here, and my Tribes ping is 700 on a bad day, 400 on a good one.) BTW BeOS is on the front of the Wasington Post
  • To really decrease ping time, you need a Pentium III processor. "Don't just get on the Internet, get all over it." ;)


    Beer recipe: free! #Source
    Cold pints: $2 #Product

  • Its not a matter of the driver in Windows, but of the .inf file. The problem being that Dial-Up-Networking doesn't have an up to date enough .inf file, so it can't interpret the latest "CONNECT" messages from the output (simple pattern matching...and I do mean simple) so, without the ability to parse/interpret the CONNECT message for the actual connect speed, Windows falls back to displaying DTE speed (ie, serial port speed). No magic here. Go grab the latest .inf file for your modem and you'll quit seeing 115,200 connections, almost assuredly.

    Jeff
  • I think just about anyone who takes these sort of things seriously enough to spend money would get a better connection then a modem. Especially from 3com. :) I hooked up a cable modem through mediaone for $40/month and it flat out makes any analog modem unacceptable. and $40 isn't much more than an isp+phone line. and the driving force behine it was a better gaming experience. I've never seen a modem get better pings than 200, but it was usually about 330. I hear dsl is about the same as cable, and i get 10-70 ping most of the time. Of course all of these numbers depend on the servers, etc.. It's actually really sad to me that they still make modems. They're such a waste of time and money. (and yes, I would have moved somewhere if dsl/cable wasn't available where I lived)
  • The problem is that it doesn't always work. For some reason when my school recently upgraded half of their modems, I stopped getting connect speed messages from the modem (CONNECT instead of CONNECT ) about half of the time (go figure). I don't know what causes this, but I suspect there is some sort of communication that used to go on between the modems that doesn't anymore.
    And no my modem isn't broken, my roommate has the exact same problem with his modem.
  • I know that my modem (A Diamond SupraExpress 56i Voice) works in Linux with no hassle. Put it in, echo ata > /dev/ttyS0, it works.
    couldn't be simpler...

    If you ask me, those 'winmodems' are just sound cards with phone jacks. I would want a hardware modem even if I was using only windows...

  • These days a modem decodes the incoming analog signal (carrier tone(s) modulated into jumps within a 2D constellation in an IQ phase space) with complex DSP algorithms that funnel ultimately into a decision algorithm that spits out ones and zeros.

    Maybe 3COM has come up with a new way of implementing the DSP RX recovery algorithm that reduces latency (for example not using as many delayed sampling taps, sampling the incoming signal at a higher rate etc). I doubt they could do much with the transmit side.

    All in all, they might be able to reduce your modems contribution to ping latency by a small amount (ms's, 10's of ms?) but it is likely swamped by normal variability in the quality of service in the rest of the net.

    Conclusion: maybe not a lie but still mostly marketing nonsense.
  • There is probably no real new technology involved in this product.
    They probably put some more hardware to let the host cpu do less work than a traditional winmodem. They selected the hardware amelioration that would allow to reach the specific need of a gamer (less delay, faster decompression, ...).
    Maybe they put some tibits to allow better connection reliability if the ISP is using 3COM modem.

    The thing you have to be aware of, is that the analog modem market will probably shrink in the upcoming years (with the proliferation of cable and dsl modem). Also the modem technology has not evolved a lot in the past year (they are partilly blocked by the FCC). So to keep market share they have to use all kind of marketing technique to attract customer. One of the technique is to make the customer believe that they purchase something that fit theire special needs (in fact, they will probably market the same modem with a different product code and name to other market segment).

    This is a well know marketing strategy when a market is saturated. They don't improve the product, they improve the packaging.

    SeeU
  • Perhaps they're twiddling the MTU on the dialup line also? Reducing that from 1500 to 576 can give you a better response time at the expense of overall bandwidth (and annoying the routers along the way). I STR some Windows columnist banging on about this about 8-9 months ago...

  • Advanced Ping Technology (Score:3)

    by Chacham ( 981 ) on Friday October 29, 1999 @04:40AM (#1578165) Homepage Journal
    In a 1998 survey of various ISPs, it was noted that 57.9% of computers ping to stay online. Problem was, it was wasting too much processing time on the server, causing some ISPs to have special servers just to respond to pings. That was all dandy until some kids decided to play "ping-pong" with the servers in a synchronized attack, and brought the ISP to its knees.

    Well, one Admin decided it was time to get back. He logged three days worth of pings from the most used accounts, and started responding to pings that didn't exist. The hack that the guys wrote to ping the computer in the first place was not ready for it, and took down the computer.

    The Admin spread the news, and it caught like wildfire. Soon there were many variations of the program and each added it's own flavor.

    Then it hit. One guy realized that the amount of time responding to valid pings was double what it should be. But if the ping response was sent at the same time as the ping, it would cut the time down to half.

    Working on this theory, and collecting average ping reports. Mike Roe Chip, Network Administrator for ISP Communications, designed a protocol in which the ping responses are sent out at the same time as the ping itself. It's is correct 99.99999 percent of the time, according to his Pentium(TM) based calculations. To make up for any incorrect responses, it sends out a Ping Response Cancel Packet. The new protocol is called DCPP (Detect and Correct Ping Protocol), based on APT (Advanced Pinged Technology), and is coming soon to servers in your area.
  • This is not what they do, but theoretically, couldn't you improve performance (and decrease compatability) by making a modem with PPP&TCP/IP in hardware. Something that does the protocol encapsulation in hardware once it knows the setup. Negotiates the PPP and sends the info back to the OS after connection? Less IO to the modem (which IS an issue with externals) and better "heuristics" for knowing when to dump a packet. The PING could be faster simply because the delay of the modem waiting for the ICMP packet to get encapsulated and sent to the modem is gone. THe modems could be pinging each other, not the PCs. By the waay, the post from Effugas (effugas@best.com) is 99% likely as the right answer.

  • Re:Read the article closer... (Score:5)

    by killbill ( 10058 ) on Friday October 29, 1999 @04:43AM (#1578168) Homepage
    Actually, it is much more sophisticated then simply detectecting dead frequencies, and moving the signal around, and in fact it was thought of sooner, and has been done for a long time.

    Think of the signal coming in as a spectrum (like winamp shows you in it's default mode). This is basically a bar graph, with frequency along the bottom axis and power on the side axis. When somebody starts jamming on their bass guitar, you get bumps in the low frequency end. When they start playing the flute, you get bumps in the high frequency end.

    As a side note, I believe mp3 encoding takes advantage of this concept to achieve it's high compression rates. It (metaphorically) saves the height of the bands, and reproduces those on playback. The higher the number of (more narrow) bands, and the more accurately you measure their height, the better your sound reproduction.

    Any transmission medium will distort this spectrum to some degree. If you look at the spectrum on the sending end, and the spectrum on the receiving end, you will see it changed.

    Your average phone line has a pretty narrow spectrum that it can transmit. I think it ranges from about 500hz at the low end, to 3500 hz at the top end. A normal CD reproduces sounds from 20 hz to 20000 hz. Unless you are a pre-pubescent female, you likely can't hear much above 15000 hz. ( hz=Hertz, cycles per second).

    So anyway, if you want to get more bandwidth (lower lows and higher highs getting crammed through a phone line), there is a neat trick to doing it (which is also used by Bose on several lines of their speakers with great results).

    1) Send a known signal through your transmission medium.
    2) Receive that signal, and compare it to what you sent.
    3) Before you send your next signal, pre-distort it, so that when your transmission medium reshapes it, it ends up at exactly the shape you wanted in the first place.

    It's kind of like buying jeans that are not pre-shrunk... by them long, so that when they shrink after being washed they end up the size you wanted.

    Simple, huh?

    The reason this is becomming more and more common, and that data rates are so amazingly high for such lousy transmission mediums like phone lines, is that heavy duty signal processors are just now becomming affordable enough to embed in consumer devices. It's been around for quite a while, you just could not afford it.

    Signal processors (DSP = Digital Signal Processors) are simple computers that have very limited functionality but do their job blindingly fast. This functionality is now to the point where it can be embedded in a single chip, and sold for a few bucks, but the engineering that goes into these things is staggering.

    There are other methods of error correction that were necessary to get data rates up the 56k speeds we now see, but they are pretty complicated.

    Bill Kilgallon
  • Stuart Cheshire wrote a pretty good article about latency a while back. TidBITS picked it up, so you can read it there.

    Part One [tidbits.com] Part Two [tidbits.com]

    As others have pointed out here, you can trade bandwidth for latency, by such tricks as not trying to compress. In the Cheshire article, he mentions that the Apple Geoport semi-modem should have been able to reduce latency considerably, by knowing when a packet was complete (but didn't). The same argument applies to WinModems, if I understand them correctly. But I bet they don't do that either.

    Anywyay, whether this thing actually works, it certainly is technically reasonable.

  • Line Probing? Heheheheh good one Beavis...

    It probably just shifts frequencies and so on to test which signals are least likely to have interference due to line static. Then it uses those. Which is a bit interesting.. Makes you wonder why the hell something like this wasn't invented years ago.

    It was. Back when the highest standard speed was 9600 bps, Telebit's "PEP" modems achieved 18000 bps by splitting the line into 511 separate frequencies and not using the less reliable ones. Obviously this protocol was proprietary, so you needed PEP modems on both ends to make it work. Pretty good modems, in my experience.

  • A common misconception is that some of the new midspeed connects such as ADSL or Cable give low pings because they have a lot of bandwidth.

    High bandwidth and low latency ("low pings") may be connected, but probably no where near as tightly as most people think. It depends on the characteristics of the system in question.

    Rather, it's the lack of PPP. PPP adds about 140ms onto the ping time, because of the way it's designed: SLIP looks like it was written on the back of a paper napkin. PPP was. :)

    Hmm, I'm loath to shout "Bollocks" in a public forum, but... I get about 160-170ms RTTs over my POTS modem. I don't believe PPP is responsible for 140ms of that. After all, do you think Cable and ADSL providers would be switching to PPPoE if PPP was so bad? I've poked around a bit in the Linux PPP driver, and it looks OK to me (not that I'm an expert in such things).

  • How? (Score:1)

    by iota ( 527 )
    Just curious, but how can an analog modem overcome the shortcomings of the phone line? I don't see how, unless there is some kind of compression -- but that requires upgrades to the ISP hardware also.

    3com, please enlighten us!

    jason
  • All PCI Modems are NOT WinModems. Contrary to popular belief, an increasing number of new PCI modems are being released with controllers and hence with some configging WILL be compatible with Linux. There are even 2 companies (Actiontec & forgot the other one) which actively promote or even support their PCI modems as Linux-compatible.

    Go to the semi-official Linux Modem Knowledge Base for more information on this:
    http://www.o2.net/~gromitkc/winmodem.html [o2.net]

    As far as 3Com/USRobotics PCI modems are concerned, MOST of their PCI modems are WinModems (all of them until August 99). The 3CP5610 released in August is a notable exception that has already been configured for DOS & Linux by many. Its apparent "Voice" version, the 3CP5609 is unknown compatability, but it is EXPECTED to work with Linux.

    The brand new "Internet Gaming Modem" is model 3CP5613 which follows the above naming pattern which MAY indicate its non-WinModem status. Please note that all previous 56K 3Com modems (before 3CP5610) had a naming scheme of: 00056XX or 00056XX-XX whereas these NEW modems are: 3CP56XX.

    Additionally, I'd like to add that I called 3Com over a week ago to ask them what PCI modems were NON-WinModems and they basically had no clue. Two different Tech Service people had never even heard of the Gaming Modem. One person told me the above-mentioned 3CP5610 wasn't a WinModem, and one told me that it it was. (it's NOT a WinModem since its already been used in Linux). Additionally, one tech person told me the 0005690 PCI Voice Modem is a hardware (controller modem) and should work in Linux since the box doesn't say "WinModem", but this is totally FALSE since according to both the above Linux Modem Database and other sources, this modem is NOT LINUX COMPATIBLE... What does this mean? Basically you can't trust the 3Com sources because they don't know what the hell they're talking about. And you can't be sure if a modem without the "WinModem" or "for Windows" designation is really Linux-compatible.

    BTW: If anyone is interested in getting either the 3CP5610 (LinuxCompatible) or Gaming Modem 3CP5613 PCI Modems for cheap, go to www.valueamerica.com [valueamerica.com] and use your ValueDollars for 1/2 price (assuming you already knew about that scam, since your chance for 120 free ValueDollars ended Thursday night). You could buy either modem for $60 using ValueDollars. The sweet Linux-compatible 5605 External Serial&USB modem could be purchased for $200/2 = $100 also. VA also has a ton of other modems that may or may not be Linux Compatible. Just note that of the 4 3Com modems with $20 rebates (that expire October 30!!) only the 5687 Internal ISA and the 5686 External Serial are Linux-compatible.

    On a final note: I will agree that a 56k PCI Modem is a bit overkill for a low bandwidth device, but ISA seems to be going the way of the dodo, which leaves us PCI, external Serial (is this being phased out too??), or external USB (with Linux USB support in dev)... You make the call!
  • I'd imagine a heavy-duty pr0n session would be just as demanding; why just concentrate on gamers?
    I suppose it's so they can market an Internet Gaming Modem rather than... well, my first few thoughts on what they could call it are pretty tasteless. I'll spare you all. This time.
  • How does MY modem being more stable help me, unless the ISP's all use these "gamer" modems as well.

    My firmware can be as stable as all hell, but if my ISP is using some $10 winmodem I'm screwed...

    Oh but wait, we ALL know that ISP's upgrade their hardware especially for the 5 users of theirs that need it, right? :)
  • There are some things they can do to increase their latency.

    I think you mean improve rather than increase . A gamer's modem should have low latency, because high round trip times are bad for interactive response.

    You are right though in your basic premise: There are various tricks the modem folks can pull to speed up modems. Probably the most effective trick would be to recognize IP/PPP/SLIP packet boundaries and use those as the quanta for compressing/error correcting, rather than the current "dumb wait" that modems currently do. (This was mentioned in an article linked elsewhere in comments.) Another would be to disable compression entirely for games, since it doesn't help much anyway -- the packets are too small.

    As for analog vs. digital latency: The POTS network (POTS == Plain Old Telephone Service) is mostly digital anyway. The analog line you have in your home is usually converted to digital fairly quickly. The D/A in your modem coupled with the A/D in the POTS network do add some latency, typically equal to a couple sampling periods. At 8000 Hz, that would amount to around 1ms, if you assume a total of 8 sampling periods worth of conversion time and buffering.

    --Joe
    --
  • 3Com's website talks about how great this will be for gamers, but I think any Internet user would like more reliable uptime, faster connections, and faster pings. Why is this limited to gaming... it sounds to me like a scam to sucker all those high school gamers into buying a new modem, while real techies ignore it.
  • It could just be that this is a real modem, and they're comparing it to competitor's winmodems...The software-to-make-up-hardware bit would have to hurt another modem's performance while doing something cpu-intensive...
  • It'd be my assumption that these feats are achieved by being a hardware based modem rather than the all to standard software based modems. Anyone know if that is anywhere near true?
  • yep the next step in modem technology
    diamonds new ULTRA QUAD SUPRA SONIC 4 modem!!!
    binds four telephone lines together for a maxium thouroughput of 256k a second with the new railgun software you can lower your ping times in half and download large files in a fraction of the time a traditional 56k .... only $220.00

  • It was a joke! =)

    The second part of my message actually details the way they could improve, not the speed of the connection, but the reliability of the communication between modem and ISP.

    No matter what they do, though, 56K is the maximum that the FCC (and, AFAIK, the rules of physics) allows on a normal analog line.

    So: faster speed is not possible, unless you switch to a digital (ISDN for instance) line. But better reliability may be possible -- again, we won't know unless 3Com gives away more info.
  • By disabling compression and error checking, it may decrease the latency of the modem.
    Thus for reasonably phone line quality, ping packet and game synchronization packet may be delivered faster.
    however, i doubt it if the phone line is very noisy, which increase packet drop (cause game stop for a moment or laggy)
  • There's something else that must be considered here: how exactly did they test the modem in order to establish the speeds of pings?

    If you want a realistic idea of what to expect, you should have a couple of phone lines installed and an "ordinary" modem and the new thing both in / attached-to the same machine, and try pinging simultaneously, at the same speed connection, for a long while. Then you flip the modems over to the other line, and try again.

    What's the point in something that manages to respond faster to ICMP pings anyway - is it an established factoid that games like quake2, say, do a lot of pinging compared to real data?
  • I could be waaay off base here, but after setting up a QII server for some colleagues of mine, I noticed that the ones who had a 28.8 connection seemed to be zipping around much better than my 53 connection....
    I checked the radius files and found out that RD/TR was 26.4/28 for them and 31.2/53.3 for me..... now what I was wondering is that since the Ratio of the Transfer and Receive is greater on the faster connection, would that cause latency/lag in gameplay.... It would seem to make sense that as the ratio of I/O approches 1:1, that response time would be better.... So if that rings true, wouldn't a 33.6 modem or 28.8 modem be a better fix????? Then again I guess I could just run a RF antenna to the roof of the office and setup a receiver at home... or hell, just run CAT5 across the street :)

    Just wondering if this made sense to anyone else

  • Henderson Labs... (Score:3)

    by mwalker ( 66677 ) on Friday October 29, 1999 @04:57AM (#1578191) Homepage
    So the 3com article says that an independent testing laboratory found that the game modem was 43% faster than other modems when connected to a 3com Total Control server. Here is the independent testing lab, and it's documents describing their test setup/testing methodology:

    Henderson Labs [henderson-labs.com]

    I have submitted a request to henderson labs to make the 3com test results publicly available. Please don't spam these people, I will post the results if/when I get them.

    Can a modem be made better for gamers? You bet. Same way a protocol can be made better for gamers. It's all about LATENCY...
    Why do we use UDP instead of TCP for gaming connections? Because we don't care about checksumming (checking for correct data) or compression (more data faster on average, but higher LATENCY), or RETRANSMISSION. That's the big one folks, retransmission. In a game, if you've lost a packet, you don't want it retransmitted anyway, because it probably is carrying the co-ordinates of a guy who's already killed you 10 seconds ago anyway. If you're tranferring a file, you definitely want that packet. (:

    Real-time applications (read: games) need low-latency connections above all else, even an unreliable connection. Normal I/O needs reliable SAR (segmentation and reassembly). Those are very different goals.

    Here's the REAL question: Does this modem do anything you can't reconfigure a normal modem to do using the hayes command set? Does it turn off some retransmission features that we can't normally turn off ourselves?

    Or is it just a different set of default flags bundled with some lame games for l33t hax0rs in time for christmas?

    3com, here is your chance to speak up. Engineering btw, not "product management".

    -I am Jack's identity crisis, in full gear.

  • Techniques to speed up a modem (Score:3)

    by cribeiro ( 105971 ) on Friday October 29, 1999 @04:58AM (#1578192)
    There are two main techniques to speed up the modem. One was explained by other posters here: it's simply a matter of disabling time-consuming tasks such as compression and error correction. The second one is to use a faster interface between the modem and the operating system. I'll comment the two.

    1) Compression in most modern modems is done using the V.42 specification. V.42 is actually very complex protocol which specifies frames that can be compressed. So you have to buffer data before compressing and sending. Error correction is done at the 'frame' level. There is a minimum latency to fill up the buffers before transmitting data.

    Bottom line: If you disable V.42 you can subtract some milisseconds of your typical latency time. The connection is less reliable and have less bandwidth available, but its better for games.

    2) The old fashioned UART interface is very slow. Even a 16550 uses a very small buffer for today's standards. This is one of the reasons to use a USB modem for better gaming experience. If this is a Winmodem, thay may have opted for a faster interface to transfer bytes from the CPU to the modem. Maybe they are using something like an ethernet interface, with larger packet buffers.

    Bottom line: its possible to have a faster modem by using a faster interface instead of a plain UART.

  • Hello from 3Com! (Score:5)

    by Archeopteryx ( 4648 ) <benburch@@@pobox...com> on Friday October 29, 1999 @04:59AM (#1578193) Homepage
    Hi!

    I'm an engineer in the 3Com modems group. The Game Modem is optimized for small packet sizes. Most games use tiny packets to indicate stuff like rudder position and etc, so this works better. Of course, short-packet pings fall into this category, too. Also, we ship it with some quite nice games in the box.

    And, yes, it works just fine for the traditional things you use a modem for.

    Happy Halloween!

  • Now, disabling modem compression is a well known tactic for decreasing ping time, and tools have been out to reconfigure Windows to do thus for years. That doesn't necessarily mean, however, that all these modems have different is a new driver disk.

    Heck, new drivers shouldn't even be necessary. If I remember my AT command set, a simple AT&Q0 should kill both error correction and data compression.

  • You can't assume PCI == WinModem. What about those Actiontec call-waiting modem thingies? Those are PCI, and no, they are not WinModems.
  • Heck, new drivers shouldn't even be necessary. If I remember my AT command set, a simple AT&Q0 should kill both error correction and data compression.

    If I remember right, there are even lower layers of error handling built into the analog signal handling.

    Of course, now we're completely outside the range where I have a technical fucking clue, so we'll have to wait for someone with more knowledge of V.90 to step in.

    Yours Truly,

    Dan Kaminsky
    DoxPara Research
    http://www.doxpara.com
  • The line probing thing is probably just line amplificatoin, which my ISP will change for me if I ask. More is not better in this case, the right ammount will get the best out of a 56k modem. All this modem does (if your ISP has their tech) is do this on-the-fly. I think.
  • Do they just ping faster thanks to an all-new, top secret ping optimization ASIC or is the *throughput* faster - as it should be? How much faster than 53Kbps ya gonna go?

  • Lower latency (Score:1)

    by Anonymous Coward
    I'll bet 3Com just modified their V.42 protocol handling. This error correction and data compression packetizes data being sent between modems, resulting in a more reliable, faster connection; it also removes the need for start/stop bits for each byte transmitted, increasing the efficiency by 20%.

    Most modems use a most-efficient method of building their packets; they'll absorb bytes 'til either the buffer is full or there's a pause of more than a certain length in the data stream, and then the packet is built and sent out.

    My guess is 3Com looks for a large number of short bursts of data, and then switches to an alternate algorithm, sending a packet out each time any pause in the data stream is detected. It may also forego compression, depending on the amount of bandwidth demanded by the connection. By taking these steps, yes, you would significantly decrease the amount of time taken between the point when the modem receives data and when that data actually heads up the pipe.
  • Hmmm... wouldn't it be nasty if USR made a slightly faster modem, but actually did some major tweaking for ICMP ping packets themselves? That is, offer a really short key to represent an ICMP request, and another short key to represent and ICMP response.

    Has anyone else noticed that they concentrate so much on PING TIMES and not latency?
  • >Makes you wonder why the hell something like this wasn't invented years ago.

    It was. Telebit was doing this 15 years ago, and I most sincerely doubt they were anywhere near the first.
  • It is very easy to reduce the ping times on analog modems. Just turn off data compression! This adds signifcant latency to the data transmission for the compression and decompression on the other end of the data. It does "add" bandwidth for compressible data.
  • And, yes, it works just fine for the traditional things you use a modem for.

    Including Linux? Someone made reference to it being a LoseModem.

  • ... and make sure that the One True Ping is still there.
  • If I remember correctly, the USRobotics modems (at least the Courier) are powered by an 80186 tied with one or two TI DSPs. Granted the DSPs do most of the work, but the 80186 handles the compression and shaping of the signal. The 80186's, depending on the version of the Courier you're running, is either 20 or 25MHz. The Sportsters, if I am guessing correctly, is simply the same guts as a Courier isn't flash upgradable?

    I guess they could make their modems better (ping time, at least) by increasing the MHz of the processors. The part about having to connect to TotalControl or other types of ISP server hardware may sound a little funny, but it has always stood as a fact that modems (since v.32 and v.32bis) perform their best when connected to the same brand/model on the other end of the phone. If you read the older magazines rating the v.34 modems, you'll remember that USRobotics Courier modems were always the top performers. If the article was worth its salt, it would also have performed a speed test against different brands (read: Courier/Zoom, Courier/BrandX, etc); the result was always that the models always got their highest numbers when talking to the same model on the other end.

    Doesn't matter to me, I've got DSL ;-)

    --

  • I switched from some 3com/usr modems, i had tried the sportster, and the old "Faxmodem".. it just didn't get the job done. I'd ping from 225 and up.

    Then i got the Diamond 56k Supra Express ( USB )

    Heaven.. I ping from 110 and up on most servers, actual ingame ping stays pretty consistant at 175-225.
  • This got moderated to redundant, yet it contains the only reference in the entire story to the actual web site of the "independent testing laboratory" mentioned in the article, and the only link to their testing methodology.

    How can unique information be redundant?
    Inquiring minds want to know!

    I am Jack's grievous need for meta-moderation.
  • Regardless of whether they can actually do some trick to reduce latency, it sounds an awful lot to me like another marketing scheme to differentiate their product and create demand.

    Analog modem technology has run its course, and most people who would buy a modem already own one or would buy a no-name for less money. Creating a trick modem gives 3Com the chance to make their product different than the sea of other identical 56k modems.

    Then there's the ISP effect. If they should prove popular enough, they may create enough pressure on ISPs to adopt this new "technology", enabling them to sell firmware options to ISPs with digital modem pools.
  • http://www.tidbits.com/netbits/nb-issues/netbits-0 15.html#lnk2
    1. 3Com doesn't really see their modem line as a revenue stream anymore. Compare their releases of new firmware(i.e., never, and you pay for upgrades that add functionality -- you can NOT get bugfix upgrades from them at all) with Lucent's. Lucent makes hated Winmodems but they release new code ~ every 3 weeks, usually greatly increasing fucntionality.(On my LT Winmodem, simply updating code increased throughput about 1.5 k.) Anyway, 3Com has gotten bad about supporting their analog modem line -- they want everybody to use xDSL and they want to sell the equipment for that.
    2. As another poster noted, one of the most _famous_ causes of bad Quake performance was an ISP with a TCS rack. Check here [808hi.com]. 3Com has never addressed this issue at all, and, indeed, Quake was unplayable through my former ISP, who used Total Control equipment. (I have cable now.)
    3. Everybody is astutely assuming that the error-control code has either been revised, or turned off. Hmmmm...
      1. Minute incompatibilities in error control protocols are one of the most common causes of failed/dropped connections. If they've mucked around with it too much...
      2. On many marginal line phone lines, connection isn't even possible without error correction. You have to get at least enough data through to start PPP
      3. Will these modems have "gaming" and "non-gaming" modes endusers can access with an AT command? I'm picturing people getting great game performance but taking 6 hours to download q3test with a non-error-corrected, non-compressed connection. And how many users will know to alter their initialization string depending on what they're planning to do online?
    5. One of the biggest problems for modem manufacturers is that modems are viewed as an undifferentiated product by all but a few consumers. If you doubt me, check comp.dcom.modems and look at how many complaints of poor performance involve Rockwell HCF (crap) or PCTel modems(worse crap)-- both economy modems bundled by corner-cutting OEMs. After all, all modems are the same, right? There's no need to pay for quality. Given that mindset, how many people will buy this thing?
  • Ok I got a response back from Henderson Labs, here it is: (my comments follow)

    [my name removed],
    Thanks for your inquiry. To answer your specific question: Test details are available from 3COM. We wrote a collateral brochure for them that they've asked exclusive distribution rights on.
    If you have an interest in any of our testing or certification services we'd be glad to supply more descriptive information and/or fee schedules.

    Sincerely,

    Warren L. Henderson, Jr.
    President

    eml: [his email removed for his protection]
    smt: [his info removed for his protection]
    tel: [his tel removed for his protection]
    ************************************************ ********************

    The information in this email is confidential and may be legally privileged. It is intended solely for the addressee. Access to this email by anyone else is unauthorized.

    If you are not the intended recipient, any disclosure, copying, distribution or any action taken or omitted to be taken in reliance on it, is prohibited and may be unlawful. When addressed to our clients any opinions or advice contained in this email are subject to the terms and conditions expressed in the governing HCL client engagement letter.

    ************************************************ *******************

    -=end letter=-

    So this thing says that the test results are available from 3com. Only I've searched their web site as thoroughly as I know how (read: perl-bot | grep ["game"&&"modem"]) and I can't find this brochure that 3com has exclusive rights to.

    Someone claiming to be from 3com engineering has already posted once. How about hosting that brochure for us, huh guys?

    Also notice the legal-bloat at the end of the message that seems to indicate they've been through the legal wringer once or twice. Interesting. Also notice I'm violating the hell out of their "email license" by posting this here. Too bad for them it's unenforceable.
  • Hmm... that's an interesting concept, and I'll bet money somebody's done it or is working on it...
    You're basically suggesting building an NIC onto the modem, then teaching it PPP?
    This is valuable for one thing, as I see it, and the value of it CANNOT be overstated:
    IT TAKES THE RESPONSIBILITY OF ONE MORE THING AWAY FROM WINDOWS. I for am all for it. :)
  • Santa Clara, CA -
    Sparked by the success of 3COM's new "gamer modem", modem manufacturers are racing to provide specialized modems to target audiences. Some recent offerings hitting the market this week:

    AOLmodem - Internet giant AOL is offering a new modem this week that requires no phone line and boasts connection speeds of up to 1.7Mbps/sec. The modem is based on AOL's revolutionary "digitized FM noise" technology and will stream random bits into the users' computer at near LAN speeds. Andrew Taylor of AOL product management had this to say: "Like they'll be able to tell the difference. Ya right."

    l33t-m0d3m: - Designed for the experienced script kiddie, this offering from L33t Designs Ltd. is a standard 56k V2 modem with the addition of quote "a whole bunch of blinking LED's that look cool". The modem also features a black metallic paint job and a leather hip holster, and comes bundled with "S.A.T.A.N".

    J-pegger Plus: - Playboy's first venture into the consumer electronics market is this sleek velvet-covered modem. Optimized for what Playboy calls "maximum Internet suction", this modem includes software for automated binary attachment reassembly and hardware-optimized UUdecoding. A nozzle on the side of the modem acts as a plentiful "personal lubricant" dispenser, and the product comes bundled with a product Playboy calls the "Monitor Splashguard(tm)".

    -mmm 0:flamebait.
    (I'sa plead guilty, yo honor)
  • or here: http://www.bolo.net/cheshire/papers/LatencyQuest.h tml

  • Re:Hello from 3Com! (Score:4)

    by Archeopteryx ( 4648 ) <benburch@@@pobox...com> on Friday October 29, 1999 @05:56AM (#1578227) Homepage
    The Gaming Modem is not a WinModem(tm). It is a traditional, or "Controller-based" modem. So, I can see no reason why it should not be usable in Linux with a minimum amount of hassle. Mind you, I have not tried this myself (yet).
  • Besides it says right in the article that the modem is controller based..thus not a winmodem.

  • It depends. It sounds like the improvements are mainly for small packet interactive stuff. If you're downloading dogfelch.mpg, it's not going to be better. OTOH, if your pr0n is interactive (e.g. a FuckU-FuckMe [fufme.com] device, MUDsex, whatever) then yeah, this'll be a Good Thing.


    ---
  • I single handedly created a faster modem in my basement. It allows someone to connect to their ISP at over 256K over copper wires...but u have to but up with the add banners while u browse...

  • Watch out, I've heard of those, and it turns out that they are actually WinMousepads. Yep, they only work with 'doze, and they won't release specs so that you can write drivers for other platforms.


    ---
  • Am i the only person who finds USB modems an inherently bad idea? I have nothign to back this up of course. Call me nostalgic but I prefere a nice HARDWARE external modem. Something stirkes me as solid about my hayes 56k dealie I bought a few years back. Course I've got cable and a DSL line now but still......
    "We hope you find fun and laughter in the new millenium" - Top half of fastfood gamepiece
  • Most indie ISP's who are owned and runn locally usally keep their equipment pretty up to date. I know we constantly upgrade our V.90 code to try and eliminate has many Interoperability issues as possible. We currently are testing a new Cisco Access server as well. Unlike the Big mega corporations where they just rent Dial ups from Mega Pop or UUNET who usally allow connections with anything including those old "baud" modems. If your connecting through AOL I could see how that modem might not be to helpful to you. =o)
  • Besides the other poster here pointing out that modems don't have MTU's per-se...

    The MTU is extremely unlikely to affect games. Quake, et al. tend to use very small UDP packets...rarely (if ever?) the size of typical MTU settings (576, 1500), so, as long as the packets are smaller than MTU, the MTU setting really has no affect.

    Jeff

  • Actually, if they wanted to make it a better gaming modem, they would "optimize" it for real data, and make pings slower! You want your ping times to be slow, in order to lure the other players into thinking that you're not as responsive. :-)


    ---
  • Some people have called bullshit on all of this, claiming that nothing can be done.

    Smarter people have suggested that there is room to improve ping times by better buffer management and shorter latencies in the transmission pipeline.

    One thing I don't think has been mentioned (but I may have missed it) is that one way to acheive better buffer management is to make the modem smart enough to look for an end of frame signature. If it detects one, it should imediately compress the data in its buffer and forward it over the line, rather than waiting for the buffer to fill if data is still coming in or a timer to expire if it is not.

  • this from a guy who quote Aleister Crowley (Diary of a Drug Fiend) in his .sig... :-)
  • I think any Internet user would like more reliable uptime, faster connections, and faster pings. Why is this limited to gaming

    Notice your use of the word "faster". What exactly does that mean? For a real world example, let's say you have a choice between an SR-71 (hypersonic spy plane), a 747 (jumbo jet), and the Exxon Valdez (supertanker) travelling from New York to London. Which vehicle would be "faster" to move:

    1. one person?
    2. 200 people and their luggage?
    3. the Statue of Liberty?

    Web surfing, file downloads, and online gaming all have different speed needs. Most people focus on bandwidth -- getting a 10Mb video in the least time, and who cares about a 2 second delay at the beginning. But for games, you want small blips of data sent without delay, every millisecond counts, and who cares if the overall data rate is lower.

    Stuart Cheshire wrote an excellent lecture about this problem years ago. Click here [bolo.net].

    A real shame it's taken so long for anyone in the modem business to pay attention. Also, it sounds like 3Com's solution is proprietary on both the user and server ends, meaning you can't just buy a new modem and run.

  • too much crack in the moderator of the day's pipe i would venture....by the way...i really dig on the fight club style quote.
    "We hope you find fun and laughter in the new millenium" - Top half of fastfood gamepiece
  • ".. anyone else get the idea that maybe it just changes the registry from default windows network settings to "faster" ? Most serious gamers have either changed the settings or downloaded a program to change the settings for them"

    Where can I find this information?
  • I may get flamed for this, but here goes anyway.
    3COM's so called "gamer" modem is not only possible, but probable. You see I work for a regional ISP that uses 3COM Total Control modems. There are some obvious incompatabilities with Lucent, TI, Supra, and Rockwell modems (both "hard" modems and winmodems). These modems are hard to connect with, slow, and VERY unreliable. (just for the sake of fairness a lot of 3COM modems are the same way). Now you design a modem that will connect reliably, and fast to the Total Control rack, you will see a improvement in ping times and data transfer. Total Control racks are the industry leader, and in use by more and more ISP's (both large and small) daily.
  • 3COM cards in general are faster because of the way they handle things at the packet level. Instead of waiting for an entire packet to come across before accepting it, they look at only the first few bytes of the header and if they're good then pass it through. ie - if you have a bunch of 3COMs on a hub with a large collision domain then you're performace may suck because there are *lots* more short-rounds (short packets 64 bytes). a 3COM won't always catch these. Other than that, there aren't all that many settings to really change in software. So, 3COM may have started doing this in their modems now as well, not only their NICs.

  • Re:How? (Score:2)

    by trb ( 8509 )
    It may be that this modem is "spoofing" some protocols, that is, looking at the data contents and doing something smart with it. This was originally done, I think, by Telebit 9600 baud modems, which did UUCP spoofing, and is also done by current fax modems, which may spoof certain handshaking. This typically requires pairs of modems that act as a black box, looking normal on the outside, and spoofing on the inside.
  • So is this just a buffer / latency issue where they reduce the total protocol layers between the modem and the (PCI) bus? It seems that you should be able to do some nifty optimizations that you wouldn't necessarily need for browsing/downloading (aside from streaming video), and these would help cut the time. Of course, real modems use less CPU than the winmodems, and that never hurts either, since things have to go much further into the system before they get returned... I always got better d/l speeds with my old USRs than any others at the time - but presently I'm on a cable modem 8^) which gives me an even better ping ;o)
  • I know a few (well actually quite alot) of gamers that would buy one of these immediatly. I really don't think the question with the 3com people is: "is this modem better for games than others" but:"will we be able to sell all our stocked-up modems if we slap a "for gamers" sticker on them"

    ---
  • For pr0n you want bandwidth over TCP; for gaming you want low latency, possibly over UDP (what do game servers use? TCP or UDP?). Higher bandwidth tends to lead to lower latency, but it's not guaranteed. In any case, modem bandwidth is limited to 56k for technical reasons, so you can't increase that; you can, however, put more processing power on a modem to speed it up a little.
    --

  • Read the article closer... (Score:4)

    by Otto ( 17870 ) on Friday October 29, 1999 @04:13AM (#1578250) Homepage Journal
    In fact, Henderson Communications Laboratories, an independent testing lab, concluded that the 3Com Internet Gaming modem achieved up to 43 percent faster weighted average ping times than five other competitor modems tested this October when calling to 3Com Total Control® or Ascend Max server equipment.
    As with all 3Com U.S. Robotics V.90 56K modems, the Internet Gaming modem includes x2(TM) technology to ensure backward compatibility with x2-capable modems and server equipment.

    So it only works with their hardware on both ends, but is backward compatible. Naturally. Also:

    The Internet Gaming modem also takes advantage of 3Com's exclusive line probing technology. This feature allows 3Com modems to dynamically create a signal pattern that optimizes throughput for that particular line, ultimately leading to higher levels of performance than other V.90 designs.

    Line Probing? Heheheheh good one Beavis...

    It probably just shifts frequencies and so on to test which signals are least likely to have interference due to line static. Then it uses those.

    Which is a bit interesting.. Makes you wonder why the hell something like this wasn't invented years ago. I mean, if the modems can sort out speeds and so forth between them, why not freq. as well? Would saved me a hell of a lot of redials and restarted downloads...


    ---
  • Cool as 3Com is, I doubt they managed to raise the transmission speed over copper. They talk about optimized firmware -- they probably reprogrammed it so that it gets the data out onto the PCI bus faster. That or simply upgraded the microcontroller inside (freq. up, lambda down.)

    Notice the qualification on the website, that the 43% is achieved when calling some weird 3com equipment.

  • Because your ISP uses a digital line (T1 or ISDN BRI) to serve your internet connection. They do not have banks of modems, unless it is a very old or very clueless ISP.

  • ADSL (Score:2)

    by MikeFM ( 12491 )
    I'd rather see them concentrate on making affordable ADSL based modems. That is where the real speed and stability is at. Isn't G.Lite supposed to make it so we can use the same modem on any standard supplier and works by just plugging it into the wall as with a standard modem? *sighs* I miss my T1 when I go home. :)
  • Ping times are significantly faster with the Internet Gaming modem, allowing players to get their games started quicker than ever before.

    Well, maybe it also starts faster but _if_ this is true it is more significant that you get a faster in-game experience. Indicates a non-techie non-gameplaying marketeer at work IMHO.

    In fact, Henderson Communications Laboratories, an independent testing lab, concluded that the 3Com Internet Gaming modem achieved up to 43 percent faster weighted average ping times than five other competitor modems

    Maybe if they put some test data online, I'd believe it.

    Just another hype press release/hyped product IMO.

    --Fritti
  • You want immeadiate response from a game or it is very frustrating -> Low Latency (a.k.a ping time).
    You want high download rate for your porn or it is very frustrating -> High Bandwidth.

    :-)

    The two in general improve with the frequency but there are exceptions e.g. satellite connections have very high bandwidth but terrible latency.
  • ..is the compression used to stuff more data down that dinky analog pipe! Anyone who played games over the modem in the 14.4 days will remember that turning off compression etc would speed things up.

    This is due to the fact that for it to compress, it first has to get X amount of data or give up waiting and throw in a bunch of junk filler. Now, I'm sure the timeout is quite small - but it's not small enough to not affect gameplay.

    This might be what it does, turns off the modem's compression. Might also disable MS's PPP compression stuff, as this would have some of the same effect..
  • I can tell you that quake ping times (playability in general), is less a matter of bandwidth than it is latency. All electrical signals travel at the speed of light (well near to it). The slowness involved in modems comes not from the "slowness" of the line itself, but rather from the digital->analog (phone line) ->digital process. If 3com created a chip which can do the conversion process faster, it'll speed things up marginally everything else being equal. Of course, noisy phone lines and the answering ISP play a large role, so you'll never be get a 20ms ping.....that is my understanding of it atleast.
  • Can I configure it to be a act like a regular modem as well? If so, I'd buy it just because it is a PCI controller-based modem, and there aren't too many of those around.

  • There are some things they can do to increase their latency. Faster DSPs with shorter pipelines, streamline the drivers, ect. Unless they're comparing their new modem against someone's Winmodem with crappy drivers I'm not sure there will be a noticable difference. I don't know much about the technologies they use in modems.

    As for digital vs. analog, digital signals don't propogate any faster down copper wire than analog signals. There are some advantages to going digital, but I don't think latency is among them. Unless you increase the bandwidth with the digital modem, then you can improve the latency (depending on how you measure latency).
  • If you are playing Quake, let me give you a quick hint on how to make your own Gamer Modem -- at home. Turn off all of the compression and error checking codes on your modem. Not only will you:
    1. Have better transmission times (no buffers to fill then to compress)
    2. Have better error recovery times -- NONE!
    3. Doesn't require special hardware.
    Sure, you'll probably end up with garbled packets, but thats what your TCP/IP stack is for. This way your modem won't be trying to retransmit a time-sensitive UDP packet -- you're machine will just toss it out and wait for the next one. -Jeff

  • Re:Techniques to speed up a modem (Score:1)

    by Anonymous Coward
    Even a 16550 uses a very small buffer for today's standards

    I think you're a little off-base here. Large buffers in use == latency. Think about it. If you have data sitting around idle (in a buffer waiting to be sent or processed on receive), then you have latency. I manage a few dozen cisco routers, and I can tell when I need to upgrade bandwidth by looking at input and output buffer packet depths. On the cisco, you have something like:

    Input queue: 0/75/4803 (size/max/drops)
    Output queue: 0/64/861 (size/threshold/drops)

    That shows that there are no packets waiting in line to be sent or received. Therefore, there is very little latency, and this line "feels" fast. Currently, this line is using about 1.2 Mbps out of 1.5 Mbps total, a large percentage. I used to upgrade when I used that high of a percentage of the bandwidth, but I learned my lesson (after wasting a lot of money). Now, I only upgrade when the buffers are being used, not when I use N% of the total bandwidth. Few packets in the output or input queue equal little latency. The large buffers really only help when you can't keep-up with processing for short periods of time or when you need to make your processing more efficient (by handling entire packets at a time, like you would with ethernet, but online games have more trouble with latency than processor time so that point is moot).

  • With a traditional modem, there are three main sources of latency.

    First, usually PPP is used for dialup IP connections. Unlike sync ppp over ISDN (or leased lines), it has to run asynchronous because it has no way of sending packets with the traditional command set. It can only send bytes. SyncPPP, on the other hand, sends whole packets delivered directly to the HDLC link layer. I know of no Hayes command extension that allows direct access to individual V.42 packets.

    Second, with external modems, the data needs to get converted to serial and back to parallel. This adds less latency with higher port speeds, but even at 115200 bps, a byte still takes ~0.1ms to even get to the modem. This is less of a problem with newer internal modems, which just look like a 16550 to the software, but have no serial data path because what's looking like a 16550 is a clever interface for the modem chip itself.

    Third, the modem needs to do error correction, which involves receiving a whole block (of 256 bytes usually) before it can be sent on to the computer. Anything without error correction could sometimes deliver low latency, but the first need for retransmission would ruin average latency, because the need for retransmission is not detected by the modem, but by the PPP layer above. (Imagine a 1500 byte packet that needs to be retransmitted because of a transmission error. Could take a whole second with older modems, at least 250ms with decent ones)

    The real key to low latency modems would be implementing a direct packet access scheme for the PPP driver, or implementing PPP on the modem itself (ideally with some kind of link level compression). Then, with the other side properly tuned as well, a packet could be transferred with no more latency than is needed for the transmission itself, because PPP would eliminate the need for V.42 and CCP would eliminate the need for V.42bis. And - implemented either in hardware or in software with a broad data path to the actual line interface - these would be pretty fast.

    There is some work on Linux-Softmodems underway. These should excel in latency, when finished and properly supported by pppd, because they implement most of the ideas above. They still need help, but there is source code already available here [www.enst.fr].

    Holger
  • Not all of us live close enought to the phone company to use ADSL (two line miles I think). My house is 6 line miles from the phone company even though the phone company isn't physically that far from my house. A friend who lives a block away is less than 2 line miles from the phone company. So unless the phone company decides to connect me by a more direct route, I'm stuck with a modem until cable modems are offered in my area.
  • What exactly are people attempting to ping to to determine that the times are actually better/faster? Its a well-known fact that routers and terminal servers deprioritize pings to do what they do best...which is routing and transferring packets.
  • Hang on -- how can you get a faster ping if the pinged server is down, if there is some Internet congestion or if there is a backhoe (snip!) between you and the machine? =)

    That does not make sense to me!

    On the other hand, 3Com may have improved the connection reliability and line noise with clever hardware -- but if that's the case, I'd like to have more detailed technical info on how they did it...

    Just my $0.02...

  • Probably works, but not entirely new (Score:5)

    by Effugas ( 2378 ) on Friday October 29, 1999 @04:19AM (#1578280) Homepage
    Consider for a moment that compression has a time delay factor intrinsic within it--the longer one waits, the more redundant data can be filtered out of a transmission block.

    Modems, by default, execute Run Length Encoding(RLE) algorithms, which if I remember correctly are statements along the lines of "Here's a string of 64 0's" instead of literally sending the stream of 0's.

    Of course, to *know* one is sending 64 0's, one has to operate on a 64 byte delay. So a key strategy for reducing lag is actually sending those 64 0's live rather than waiting the delay period.

    This isn't really a bad idea--waiting for the delay period when highly tuned networking applications which would *never* send such a "low entropy"(translation: almost devoid of unique information content) string is foolish.

    Now, disabling modem compression is a well known tactic for decreasing ping time, and tools have been out to reconfigure Windows to do thus for years. That doesn't necessarily mean, however, that all these modems have different is a new driver disk.

    56K modem technology has been described as the biggest technical hack the industry has ever seen, and I'm inclined to agree. That it works at all is near-miraculous(although actually it doesn't really go as fast as advertised, thus 3Com's upcoming $5 coupon slap on the wrists for claiming net connections would be twice as fast).

    Intrinisic in the protocol are error-checking codes. Error checking *also* introduces delays, as you need to wait for the data to come in before you can sum it. Reduce your error checking, or decrease the check interval, or tweak in any number of hacks, and lag can decrease.

    Also intrinsic is connection recovery--by speeding this up, making this more effective, or both, 3Com gets an edge. That there appears to be specific functionality reserved for specific ISP hardware leads me to suspect there's off-standard code being put into use.

    This isn't necessarily bad.

    I'd be interested in more technical documentation as to what they've done--anyone from 3Com got a real link for the rest of us?

    Yours Truly,

    Dan Kaminsky
    DoxPara Research
    http://www.doxpara.com

  • This is probably not a scam (Score:3)

    by Sludge ( 1234 ) <slashdot@@@tossed...org> on Friday October 29, 1999 @04:19AM (#1578281) Homepage
    I recall Carmack making a .plan update or two while he he was talking about latency while creating the first version of Quakeworld. He stated a few changes which could be done in order to decrease latency.

    What your modem does, by default, is collect all data into a buffer, and then send it out all at once. The larger the buffer, the more efficiently compression can be performed upon it. All of the old Doom init strings that came with the game turned off your compression... and your error correction for that matter. (Wasn't it ATL0&M0&N0&B0 for a US Robotics?)

    A common misconception is that some of the new midspeed connects such as ADSL or Cable give low pings because they have a lot of bandwidth. Rather, it's the lack of PPP. PPP adds about 140ms onto the ping time, because of the way it's designed: SLIP looks like it was written on the back of a paper napkin. PPP was. :)

    Having strikingly low bandwidth causes for dropped packets, which is a very high possibility, especially since most (not all) packets in Quake games are UDP. However, other than this exception, bandwidth is secondary to latency when playing Quake.

    That's why there isn't a notable latency difference between 28.8 and 56k. It's still PPP with error correction.
  • Probably the biggest killer in response time, even with a v90 connection, is going to be the compression. **NOT** the CPU time that it takes to compress and decompress a stream, but rather, the time for the stream to be transmitted. Remember that modems actually send data back and forth in groups of compressed data. One perhaps could make this faster by sending to the host the results of a stream before it is entirely decoded. But one could probably make it faster by turning compression off altogether. You'll have less *BANDWIDTH* that way, but a faster *RESPONSE TIME*.
  • That equipment is not so "weird"... It's actually a pretty common setup. 3Com Total Control and Ascend Max boxes are heavily used throughout the dialup world.
  • Duh! that 115k2 *is* the serial port speed, my dear Evil friend... don't trust what Windows says.


    Nah, don't trust how 3Com manipulated the Windows drivers. There's a difference.

    Most 56K modems actually report the real connection speed. 3Com is doing a bit of phallus-phlashing, if you know what I mean.

    Yours Truly,

    Dan Kaminsky
    DoxPara Research
    http://www.doxpara.com
  • 56K is the maximum that the FCC (and, AFAIK, the rules of physics) allows on a normal analog line.

    Both false. The FCC only regulates voltage.

    The rules of physics say you can get at least 7 mbits/sec through a phone line (contact your favorite telcos for info on xDSL), and much more for short distances (raise your hand if you've ever made a working 100mbit ethernet cable out of cat1 or cat3 cable).

    However, our current understanding of the rules of physics limits our ability to transmit more than 53000 symbols (bits) per second down the average extremely-poorly-strung non-shielded 26awg cable by modulating it at a limited amplitude (I believe it's about 5-6 volts)

    Also, to respond to another poster, compression typically increases latency.

  • Most modems have alot of extra processing to handle error correction, compression, and other things. I can imagine that a "Gamer's Modem" would cut out the non-essential steps such as V.42bis compression. It might also bypass some of the other bandwidth-enhancing tricks they do, trading bandwidth for latency.

    Also, depending on how fancy they are, they might be doing some IP-level tricks, although I'd hope they're not. (This is reminiscent of the XModem-accelerating modems of several years ago that would fake an XModem ACK to speed up downloads, since XModem didn't stream.)

    --Joe
    --

  • Hmmmmm (Score:4)

    by jd ( 1658 ) <imipakNO@SPAMyahoo.com> on Friday October 29, 1999 @04:24AM (#1578301) Homepage Journal
    Some possibilities occur to me. Some aren't restricted to games, and I don't know if ANY of them are actually used (or even usable!):

    • Better noise filtering (line-noise and noise that affects the modem directly). Fewer retransmits would get the effective speed up.
    • Intelligent buffering. Games don't tend to be as constantly draining on the net as, say, FTP. By smoothing the bursts out a little, you'd get much better throughput. (Router QoS algorithms do much the same thing.)
    • Intelligent packet-fill. If you know, or can make a good guess, as to corrupted values in a packet, you can do a best-guess fill of the damaged sections, rather than ask for a fresh copy. If only a limited range of games can benefit from this modem, and/or have to register with the modem, this would be possible to do.
    • No error checking? Action games usually don't worry if there's slight lossage - they're too fast for it to make any significant difference. So, checking for errors in transfers is a bit of a waste. It's slow, and the resends waste network bandwidth. So, simply don't implement any. (Some network games, such as Netrek, do this in software already, by using UDP. They're MUCH faster as a result.)

Slashdot Top Deals

C'est magnifique, mais ce n'est pas l'Informatique. -- Bosquet [on seeing the IBM 4341]

Close